By the same token, we might compare dark matter to neutrinos, which were a theoretical entity invoked to explain a particular set of observations on radioactivity (the shape of the beta spectrum.) Neutrinos turned out to exist.
As such, while the comparison to aether is superficially apt, it is not something we can draw any conclusions from, because the comparison to the neutrino is equally apt.
Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. It is not the discipline of testing ideas by making analogies to other ideas. There is a reason for this: making analogies to other ideas has consistently proven to be almost completely useless for creating knowledge of reality, while the discipline of science has been wildly successful.
Nor are the properties of caloric, aether, neutrinos or dark matter "magical". They are merely the ones required of an entity that is able to explain our observations in each instance. In the case of caloric it turned out to have self-contradictory properties, when the full deductive closure of the theory was teased out. In the case of aether it turned out to have properties that made predictions that were false. In the case of neutrinos the required properties made predictions that were true.
In the case of dark matter: we don't know yet, and the only way we will ever know is if we continue on with our program of systematic observation, controlled experiment and Bayesian inference. There is no other way to know.
